Modern computer network applications are designed to be generally accessible. For example, the World Wide Web is accessible via the Internet through a variety of platform, browser and device combinations. However, due to portability, cost and other factors, the platform/browser/device combinations available to users for Web access can vary widely with regard to display and presentation capabilities.
Web-based application authors writing in a mark-up language (e.g., XML, HTML, XHTML) can specify document styling (i.e., the look and feel of documents), including display fonts to a network server, which may then determine a preferential hierarchy for which display fonts to use. For example, an author may include a list of primary fonts in a font request, and then specify a hierarchy of fallback fonts when particular primary fonts are not available. Standardized languages, including cascading style sheets, have been developed for streamlining the specification of document styling in mark-up language applications.
When the onus is on authors to specify document styling, however, fallback fonts are sometimes not specified in font requests. Further, even font requests that include fallback fonts may specify primary and fallback fonts that are not available for every type of platform/browser/device combination where a document might be presented. In such instances, a document may be presented with default or inaccurate fonts when primary fonts are not available for display. Default or inaccurate fonts are not optimal solutions, as they may degrade the user experience or render certain documents completely unusable.